Guaranteed damage provides logic for decision making on what your opponent is trying to do. If you had every move in the move list do 10 points of damage and not be comboable to the next move item, would you be able to 'read' your opponent then? No, you both would be just playing a random guessing game. That's what DOA4 felt like to me, it didn't really matter what move I used, and since it didn't matter to me, the opponent couldn't 'read' me properly.
Launch combos are going to happen and eventually be static. Players will maximize the damage from the guaranteed opportunity to win the match. That's their reward for getting the launch to occur, and if they are repeatedly being hit by the same launcher then I'd question the player's ability to 'beat such a predictable player'.
Now you go into DOA3 where you have moves that are obviously 'better options' over other moves such as launching on normal hit, safe on guard, guarantee followups, and you throw in some positional space into the equation and you can logically point what would be 100s of options from the opponent to a mere 1-3 options that would be the optimum choice. In such a system, you could punish someone for just being stupidly random for random's sake like in any other instance of game theory, and the player who wasn't random but calculated instead would end up on top each time.
